code: def md_dtypes(self):
      return [
          ("symbol", "object"),
          ("start_date", "datetime64[ns]"),
          ("end_date", "datetime64[ns]"),
          ("ac_date", "datetime64[ns]"),
          ("min_trade_size", "float"),
      ]
  
file_path: catalyst/catalyst/data/bundles/base_pricing.py
imports: from catalyst.data.bundles.base import BaseBundle
  from catalyst.utils.memoize import lazyval
label_desc: Use image node_id 1 for calling the BasePricingBundle obj's underlying member method code with example usage: obj.md_dtypes() and returns: list